U.S. patent application number 14/287067 was filed with the patent office on 2014-12-04 for ink-jet recording apparatus.
This patent application is currently assigned to MIMAKI ENGINEERING CO., LTD.. The applicant listed for this patent is MIMAKI ENGINEERING CO., LTD.. Invention is credited to ATSUSHI TSUCHIYA.
Application Number | 20140354743 14/287067 |
Document ID | / |
Family ID | 50732072 |
Filed Date | 2014-12-04 |
United States Patent
Application |
20140354743 |
Kind Code |
A1 |
TSUCHIYA; ATSUSHI |
December 4, 2014 |
INK-JET RECORDING APPARATUS
Abstract
Provided is an ink-jet printer including a printer head which
ejects ink onto a medium while moving relative to the medium in a
main-scanning direction, an LED module which exposes the ink
ejected onto the medium to light while moving in the main-scanning
direction together with the printer head so as to cure the ink, and
LED light sources which are provided to the LED module at a
position near the medium, which are plurally arranged at least in
the main-scanning direction, and which are divided into a plurality
of areas in accordance with an arrangement position with respect to
the LED module to adjust an amount of light during light emission
for each area.
Inventors: |
TSUCHIYA; ATSUSHI; (NAGANO,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MIMAKI ENGINEERING CO., LTD. |
NAGANO |
|
JP |
|
|
Assignee: |
MIMAKI ENGINEERING CO.,
LTD.
NAGANO
JP
|
Family ID: |
50732072 |
Appl. No.: |
14/287067 |
Filed: |
May 26, 2014 |
Current U.S.
Class: |
347/102 |
Current CPC
Class: |
B41J 11/002
20130101 |
Class at
Publication: |
347/102 |
International
Class: |
B41J 11/00 20060101
B41J011/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 28, 2013 |
JP |
2013-112298 |
Claims
1. An ink-jet recording apparatus, comprising: a printer head which
moves relative to a table on which a medium is placed, and which
ejects ink onto the medium while moving relative to the medium in a
main-scanning direction; irradiation means for performing exposure
with respect to the ink ejected onto the medium to cure the ink
while moving together with the printer head in the main-scanning
direction; and light-emitting units which are provided to the
irradiation means at a position near the medium, which are plurally
arranged at least in the main-scanning direction, and which are
divided into a plurality of areas in accordance with an arrangement
position with respect to the irradiation means to adjust an amount
of light during light emission for each of the areas.
2. The ink-jet recording apparatus according to claim 1, wherein in
the light-emitting units, the amount of light of the light-emitting
units arranged near an outer end portion of the irradiation means
in the main-scanning direction is set to be larger than the amount
of light of the light-emitting units located near the center of the
irradiation means in the main-scanning direction.
3. The ink-jet recording apparatus according to claim 1, wherein in
the light-emitting units, the amount of light of the light-emitting
units located near the center of the irradiation means in the
main-scanning direction is set to be larger than the amount of
light of the light-emitting units arranged near the outer end
portion of the irradiation means in the main-scanning
direction.
4. The ink-jet recording apparatus according to claim 1, further
comprising: light absorption means for absorbing light reflected
from the medium, the light absorption means being located between
the printer head and the irradiation means in the main-scanning
direction.
5. The ink-jet recording apparatus according to claim 4, wherein
the light absorption means is coated with a diffuse reflection
coating material.
6. The ink-jet recording apparatus according to claim 4, wherein
the light absorption means is coated with a black color.
7. The ink-jet recording apparatus according to claim 4, wherein an
ultraviolet absorbing agent is applied onto the light absorption
means.
8. The ink-jet recording apparatus according to claim 4, wherein a
surface of the light absorption means is formed in a concavo-convex
shape.
9. The ink-jet recording apparatus according to claim 1, further
comprising: an incidence unit which is located between the printer
head and the irradiation means in the main-scanning direction, and
which transmits light reflected from the medium; and an incident
light capturing unit that captures light, which is transmitted
through the incidence unit, on a medium side.
10. The ink-jet recording apparatus according to claim 2, further
comprising: light absorption means for absorbing light reflected
from the medium, the light absorption means being located between
the printer head and the irradiation means in the main-scanning
direction.
11. The ink-jet recording apparatus according to claim 3, further
comprising: light absorption means for absorbing light reflected
from the medium, the light absorption means being located between
the printer head and the irradiation means in the main-scanning
direction.
12. The ink-jet recording apparatus according to claim 2, further
comprising: an incidence unit which is located between the printer
head and the irradiation means in the main-scanning direction, and
which transmits light reflected from the medium; and an incident
light capturing unit that captures light, which is transmitted
through the incidence unit, on a medium side.
13. The ink-jet recording apparatus according to claim 3, further
comprising: an incidence unit which is located between the printer
head and the irradiation means in the main-scanning direction, and
which transmits light reflected from the medium; and an incident
light capturing unit that captures light, which is transmitted
through the incidence unit, on a medium side.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Japan
application serial no. 2013-112298, filed on May 28, 2013. The
entirety of the above-mentioned patent application is hereby
incorporated by reference herein and made a part of this
specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an ink-jet recording
apparatus.
[0004] 2. Description of the Background Art
[0005] As one of the ink-jet recording apparatuses in the related
art, there is an ink-jet recording apparatus including a holder
that holds an ink head and ejects ink from the ink head with
respect to a medium as an object to be printed on while moving in a
main-scanning direction, and a lamp that moves in the main-scanning
direction together with the holder and emits light for curing the
ink ejected from the ink head.
[0006] For example, an ultraviolet irradiation device disclosed in
JP-A-2008-173968 includes a carriage on which a printer head
allowing an ultraviolet-curable ink to adhere to printing paper is
mounted, a carriage motor that moves the carriage in the
main-scanning direction, and an ultraviolet irradiation device that
irradiates an ink-adhering surface of the printing paper with
ultraviolet rays. Here, the ultraviolet irradiation device includes
a plurality of ultraviolet light sources, and the plurality of
ultraviolet light sources are supported by a circuit substrate in
which a mounting surface of the ultraviolet light sources faces a
surface of the printing paper. According to this, the plurality of
ultraviolet light sources face the printing paper and are arranged
in parallel in a direction parallel with the surface of the
printing paper.
[0007] In addition, in an ink-jet recording apparatus disclosed in
JP-A-2009-51095, recording heads corresponding to color ink of each
color and an ultraviolet light source that emits ultraviolet rays
for curing and fixing the ink ejected on a recording medium are
arranged in a carriage that is arranged to reciprocally move in the
main-scanning direction. The ultraviolet light source provided to
the carriage is constituted by a plurality of LEDs, and the
plurality of LEDs are arranged in rows. In addition, the plurality
of LEDs are configured to change the intensity of ultraviolet rays,
which are emitted, for each of the LEDs or for each block of LEDs
divided into several blocks so as to change the glossiness of an
image. According to this, a plurality of patches having different
image glossiness are included in one test pattern image.
[0008] In addition, in an ink-jet printer disclosed in
JP-T-2012-520779, a printing engine, which includes a print-head
configured to spray ink onto a substrate and a light-source unit
configured to cure the ink on the substrate, can move relative to
the substrate, and the light-source unit is provided with a
plurality of LED arrays arranged in a straight line.
SUMMARY OF THE INVENTION
[0009] However, in a case of irradiating the medium with light from
a lamp to cure the ejected ink, some of the light is reflected from
the medium, and is emitted to the outside of the lamp and becomes
so-called stray light, which is unnecessary irradiation light, in
some cases. When the ink head is irradiated with the stray light,
the ink may be cured at a site other than the assumed sites, and
thus it is necessary to positively prevent the stray light from
occurring. On the other hand, the stray light occurs when the lamp
is turned on to cure the ink. Therefore, it is very difficult to
emit the light for curing the ink without occurrence of the stray
light.
[0010] The invention has been made in consideration of the
above-described circumstances, and an object thereof is to provide
an ink-jet recording apparatus capable of performing irradiation of
ink-curing light while greatly reducing stray light.
[0011] To solve the above-described problem and to accomplish the
object, according to an aspect of the invention, there is provided
an ink-jet recording apparatus including: a printer head which
moves relative to a table on which a medium is placed, and which
ejects ink onto the medium while moving relative to the medium in a
main-scanning direction; irradiation means for performing exposure
with respect to the ink ejected onto the medium to cure the ink
while moving together with the printer head in the main-scanning
direction; and light-emitting units which are provided to the
irradiation means at a position near the medium, which are plurally
arranged at least in the main-scanning direction, and which are
divided into a plurality of areas in accordance with an arrangement
position with respect to the irradiation means to adjust an amount
of light during light emission for each of the area.
[0012] According to this ink-jet recording apparatus, the light
emitting units are arranged at a position near the medium, and thus
it is possible to limit the height of an optical path of reflected
light from the medium. According to this, it is possible to
suppress the light reflected from the medium from getting out from
a space between the medium and the irradiation means and being
stray light directly propagating in the direction of the printer
head. In addition, the light-emitting units are plurally arranged
in the main-scanning direction, and are divided into a plurality of
areas in accordance with an arrangement position with respect to
the irradiation means to adjust an amount of light for each of the
areas, and thus it is possible to irradiate the irradiation range
with light in an approximately uniform amount of light.
Accordingly, it is possible to suppress occurrence of unevenness in
irradiation caused by arranging the light-emitting units to be
close to the medium in order for light not to diffuse. As a result,
it is possible to perform irradiation of the ink-curing light while
greatly reducing the stray light.
[0013] In addition, in the ink-jet recording apparatus, it is
preferable that in the light-emitting units, the amount of light of
the light-emitting units arranged near an outer end portion of the
irradiation means in the main-scanning direction be set to be
larger than the amount of light of the light-emitting units located
near the center of the irradiation means in the main-scanning
direction.
[0014] According to this ink-jet recording apparatus, the amount of
light of the light-emitting units arranged near an outer end
portion of the irradiation means in the main-scanning direction is
set to be larger than the amount of light of the light-emitting
units located near the center of the irradiation means in the
main-scanning direction, and thus it is possible to irradiate an
irradiation range of the irradiation means with light in a reliably
uniform amount of light. As a result, it is possible to make
irradiation intensity of ultraviolet rays in an irradiation range
flat in a more reliable manner, and thus it is possible to cure the
ink in a more reliable and uniform manner.
[0015] In addition, in the ink-jet recording apparatus, it is
preferable that in the light-emitting units, the amount of light of
the light-emitting units located near the center of the irradiation
means in the main-scanning direction be set to be larger than the
amount of light of the light-emitting units arranged near the outer
end portion of the irradiation means in the main-scanning
direction.
[0016] According to this ink-jet recording apparatus, the amount of
light of the light-emitting units located near the center of the
irradiation means in the main-scanning direction is set to be
larger than the amount of light of the light-emitting units
arranged near the outer end portion of the irradiation means in the
main-scanning direction, and thus it is possible to reduce the
amount of light that propagates in the direction of the printer
head. As a result, it is possible to reduce the stray light in a
more reliable manner.
[0017] In addition, it is preferable that the ink-jet recording
apparatus further include light absorption means for absorbing
light reflected from the medium, the light absorption means being
located between the printer head and the irradiation means in the
main-scanning direction.
[0018] According to this ink-jet recording apparatus, the light
absorption means for absorbing light is arranged between the
printer head and the irradiation means, and thus it is possible to
suppress light, which is emitted from the irradiation means and is
repetitively reflected between the irradiation means and the
medium, from propagating in the direction of the printer head. As a
result, it is possible to reduce the stray light in a more reliable
manner.
[0019] In addition, in the ink-jet recording apparatus, it is
preferable that the light absorption means be coated with a diffuse
reflection coating material.
[0020] According to this ink-jet recording apparatus, the light
absorption means is coated with the diffuse reflection coating
material, and thus it is possible to suppress light, which reaches
the light absorption means, from being reflected in a more reliable
manner. Accordingly, it is possible to suppress light from
propagating in the direction of the printer head between the
irradiation means and the medium. As a result, it is possible to
greatly reduce the stray light in a more reliable manner.
[0021] In addition, in the ink-jet recording apparatus, it is
preferable that the light absorption means be coated with a black
color.
[0022] According to this ink-jet recording apparatus, the light
absorption means is coated with a black color, and thus light,
which reaches the light absorption means, can be absorbed in a more
reliable manner. Accordingly, it is possible to suppress light from
propagating in the direction of the printer head between the
irradiation means and the medium. As a result, it is possible to
greatly reduce the stray light in a more reliable manner.
[0023] In addition, in the ink-jet recording apparatus, it is
preferable that an ultraviolet absorbing agent be applied onto the
light absorption means.
[0024] According to this ink-jet recording apparatus, the
ultraviolet absorbing agent is applied onto the light absorption
means, and thus the light absorption means can absorb ultraviolet
rays included in light that reaches the light absorption means.
According to this, in a case of curing the ink ejected onto the
medium with ultraviolet rays, it is possible to suppress
unnecessary ultraviolet rays from propagating in the direction of
the printer head between the irradiation means and the medium. As a
result, it is possible to reduce the stray light in a more reliable
manner.
[0025] In addition, in the ink-jet recording apparatus, it is
preferable that a surface of the light absorption means be formed
in a concavo-convex shape.
[0026] According to this ink-jet recording apparatus, the surface
of the light absorption means is formed in a concavo-convex shape,
and thus it is possible to suppress light, which reaches the light
absorption means, from being reflected in a more reliable manner,
and it is possible to suppress the light from propagating in the
direction of the printer head between the irradiation means and the
medium. As a result, it is possible to perform irradiation of the
ink-curing light while greatly reducing the stray light in a more
reliable manner.
[0027] In addition, it is preferable that the ink-jet recording
apparatus further include: an incidence unit which is located
between the printer head and the irradiation means in the
main-scanning direction, and which transmits light reflected from
the medium; and an incident light capturing unit that captures
light, which is transmitted through the incidence unit, on a medium
side.
[0028] According to the ink-jet recording apparatus, the incident
light capturing unit that absorbs light, which is transmitted
through the incidence unit, from the medium side is provided, and
thus it is possible to capture more light. That is, the incident
light capturing unit can attenuate light by reflecting the light in
a large area, and thus it is possible to capture more light.
Accordingly, it is possible to reduce the stray light in the
direction of the printer head from the irradiation means side in a
more reliable manner. As a result, it is possible to perform
irradiation of the ink-curing light while greatly reducing the
stray light in a more reliable manner.
[0029] The ink-jet recording apparatus of the invention has an
effect capable of performing irradiation of ink-curing light while
greatly reducing stray light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a configuration view illustrating a structure of
an ink-jet printer according to a first embodiment;
[0031] FIG. 2 is a plan view illustrating a printer head of the
ink-jet printer shown in FIG. 1;
[0032] FIG. 3 is a view seen in a direction of an arrow A-A of FIG.
2;
[0033] FIG. 4 is a view seen in a direction of an arrow B-B of FIG.
3;
[0034] FIG. 5 is a cross-sectional view of an LED module provided
to an ink-jet printer according to a second embodiment, and is an
explanatory view of a light absorption unit;
[0035] FIG. 6 is a cross-sectional view of an LED module provided
to an ink-jet printer according to a third embodiment, and is an
explanatory view of an incidence unit and an incident light
capturing unit;
[0036] FIG. 7 is an explanatory view of a case of controlling LED
light sources in a 12-division manner as a modification example of
the ink-jet printer according to the first embodiment;
[0037] FIG. 8 is an explanatory view of a case of controlling the
LED light sources in an 8-division manner as a modification example
of the ink-jet printer according to the first embodiment;
[0038] FIG. 9 is an explanatory view of a case of controlling the
LED light sources in a 5-division manner as a modification example
of the ink-jet printer according to the first embodiment;
[0039] FIG. 10 is an explanatory view of a case of controlling the
LED light sources in a 4-division manner as a modification example
of the ink-jet printer according to the first embodiment; and
[0040] FIG. 11 is an explanatory view of a light absorption unit as
a modification example of the ink-jet printer according to the
second embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Hereinafter, embodiments of an ink-jet recording apparatus
according to the invention will be described in detail with
reference to the attached drawings. In addition, the invention is
not limited to the embodiments. In addition, constituent elements
in the following embodiments include elements which can be
substituted or easily substituted by those skilled in the art, and
which are substantially the same as the constituent elements.
First Embodiment
[0042] FIG. 1 is a configuration view illustrating a structure of
an ink-jet printer according to a first embodiment. FIG. 2 is a
plan view illustrating a printer head of the ink-jet printer shown
in FIG. 1. The ink-jet printer 1, which is an ink-jet recording
apparatus shown in the same drawings, includes a Y-bar 5 that
extends in one direction parallel with a medium M during printing
onto the medium M by the ink-jet printer 1, and the extension
direction of the Y-bar 5 is a main-scanning direction in the
ink-jet printer 1. In other words, the Y-bar 5 extends in the
main-scanning direction.
[0043] A carriage 10, which moves along the Y-bar 5, is mounted to
the Y-bar 5. Movement of the carriage 10 in the main-scanning
direction can be controlled, and the carriage 10 can reciprocally
move in the main-scanning direction along the Y-bar 5 by driving
means such as a motor (not shown). According to this, the carriage
10 can move relative to a table (not shown) on which the medium M
is placed in the main-scanning direction. On the other hand, the
ink-jet printer 1 is provided with a feeding mechanism (not shown)
of the medium M, and the medium M is movably retained by the
feeding mechanism in a sub-scanning direction that is a direction
perpendicular to the main-scanning direction.
[0044] The carriage 10 includes a holder 11 in which a printer head
15 is arranged, and ultraviolet irradiation devices 20 provided on
both sides of the holder 11 in the main-scanning direction. Among
these, the printer head 15 includes a plurality of ink ejection
units 16, and the plurality of ejection units 16 are arranged to
deviate from each other in the main-scanning direction and the
sub-scanning direction, and thus a wide printing region is
constituted. In addition, the ultraviolet irradiation devices 20
are symmetrically arranged on both sides of the printer head 15 on
the main-scanning direction and have a symmetrical structure.
[0045] Each of the ultraviolet irradiation devices 20 includes a
plurality of light-emitting diode (LED) modules 25 as irradiation
means, and the plurality of LED modules 25 are arranged in a
plurality of rows. Specifically, the plurality of LED modules 25
constitute inner rows 21in that are located near the printer head
15 in the main-scanning direction, and outer rows 21out that are
located on a side opposite to a side, at which the printer head 15
is located in the main-scanning direction, when seen from the inner
rows 21in. In addition, the LED modules 25 are arranged in parallel
in set of two in the sub-scanning direction.
[0046] A rail 21, which extends in the sub-scanning direction, is
provided to the inner rows 21in and the outer rows 21out,
respectively, and the LED modules 25 of the inner rows 21in and the
outer rows 21out are mounted to the respective rails 21 in a
movable manner in the sub-scanning direction. A length of each of
the rails 21 in the sub-scanning direction, that is, a movable
range of the LED modules 25 in the sub-scanning direction is longer
than a length of the printer head 15 in the sub-scanning direction.
The LED modules 25 are configured as follows. Each set of the LED
modules 25 can move along the rail 21, which is provided as
described above, in the sub-scanning direction by driving means
such as a motor (not shown), and can stop at an arbitrary position
in the sub-scanning direction.
[0047] FIG. 3 is a view seen in a direction of an arrow A-A of FIG.
2. Each of the LED modules 25 provided to the ultraviolet
irradiation device 20 includes a plurality of LED light sources 26
as a light-emitting unit. The LED light sources 26 are configured
to emit light including ultraviolet rays during light emission. The
plurality of LED light sources 26 are arranged in parallel in a
direction parallel with the medium M in a state in which printing
is performed onto the medium M in the ink-jet printer 1, and are
provided in a direction facing the medium M. In addition, the
plurality of LED light sources 26 are provided to be located in the
vicinity of the medium M that is printed, and are provided at a
position close to the medium M. Specifically, the LED light sources
26 are arranged to be spaced away from the medium M by a distance
of approximately 2 mm.
[0048] FIG. 4 is a view seen in a direction of an arrow B-B of FIG.
3. In each of the LED modules 25, the plurality of LED light
sources 26 are arranged in the vertical direction and the
horizontal direction on a surface on a medium M side of the
substrate 30. The plurality of LED light sources 26 are arranged in
a so-called lattice shape. That is, the LED light sources 26 are
arranged in parallel in the main-scanning direction and the
sub-scanning direction in a plural number, respectively. In the
main-scanning direction and the sub-scanning direction, the
plurality of LED light sources 26 are divided into sets in which an
arbitrary plural number of the LED light sources 26 are collected
as a group. An irradiation unit 31 is connected to each of the sets
and is capable of independently controlling the LED light sources
26 included in the set as a whole.
[0049] For example, as shown in FIG. 4, the plurality of LED light
source 26 are divided into five in the main-scanning direction, and
a portion divided at the central position in the main-scanning
direction is divided into four in the sub-scanning direction. That
is, in the ink-jet printer 1 according to the first embodiment, the
plurality of LED light sources 26 provided to the LED module 25 are
divided into eight (E1 to E8), and the irradiation unit 31 is
connected to each set. The irradiation unit 31, which is connected
to each set of the LED light sources 26 in this manner, is an
electronic circuit capable of setting illuminance of the entirety
of LED light sources 26 included in the set as a whole. That is,
the plurality of LED light sources 26 are divided into a plurality
of areas in accordance with an arrangement position in the LED
module 25. With respect to the LED light sources 26 divided into
the plurality of areas, adjustment of an amount of light is
performed for each of the areas by the irradiation unit 31.
[0050] The irradiation unit 31 is connected to a control unit 35.
The control unit 35 has a known configuration provided with a
processing unit such as a central processing unit (CPU), a storage
unit such as a random access memory (RAM), and the like. The
control unit 35 performs movement control of the carriage 10 in the
main-scanning direction, movement control of the LED module 25 in
the sub-scanning direction, and feeding control of the medium M in
the sub-scanning direction, or controls irradiation of the
respective LED light sources 26 by transmitting a signal of a
predetermined irradiation intensity to the irradiation unit 31.
[0051] For example, in the ink-jet printer 1 according to the first
embodiment, among the eight sets of the plurality of LED light
sources 26, two sets on each side in the main-scanning direction,
that is, four sets (E1 to E4) on both sides in the main-scanning
direction, and two sets (E5 and E8) on both sides in the
sub-scanning direction in four central sets (E5 to E8) in the
main-scanning direction become a strong light amount portion 36 in
which irradiation intensity is set to be strong. In contrast, among
the eight sets of the plurality of LED light sources 26, two sets
(E6 and E7) on a central side in the sub-scanning direction in the
four central sets (E5 to E8) in the main-scanning direction become
a weak light amount portion 37 in which the irradiation intensity
is set to be weaker than that of the strong light amount portion
36.
[0052] As described above, in the LED light sources 26 provided to
the LED module 25, the amount of light during light emission is
different in each case in accordance with an arrangement position,
and in the ink-jet printer 1 according to the first embodiment, the
outer peripheral portion of the LED module 25 in a plan view
becomes the strong light amount portion 36 in which the amount of
light is large, and the central portion becomes the weak light
amount portion 37 in which the amount of light is small. According
to this, in the LED light sources 26, the amount of light is larger
in the LED light sources 26 that are arranged near an outer end
portion of the LED module 25 in the main-scanning direction in
comparison to the LED light sources 26 that are located near the
central portion of the LED module 25 in the main-scanning
direction.
[0053] The ink-jet printer 1 according to the first embodiment is
configured as described above. Hereinafter, an operation thereof
will be described. When performing printing onto the medium M by
the ink-jet printer 1, the carriage 10 is moved relative to the
medium M in the main-scanning direction by moving the carriage 10
along the Y-bar 5, and the medium M is moved in the sub-scanning
direction, thereby performing printing in a wide range of the
medium M.
[0054] Specifically, ink according to printing contents is ejected
from the ejection units 16 of the printer head 15 provided to the
carriage 10 while moving the carriage 10 along the Y-bar 5. For
example, the printer head 15 is provided in such a manner that each
of the plurality of ejection units 16 ejects ink of any color among
M (magenta), C (cyan), Y (yellow), and K (black), and the printer
head 15 ejects the ink of a color according to printing contents
from the ejection units 16. In addition, a combination of ejection
colors from the printer head 15 may be different from the
above-described combination.
[0055] The printer head 15 moves in the main-scanning direction by
moving the carriage 10 along the Y-bar 5 while ejecting a desired
color of ink with a predetermined width in the sub-scanning
direction set as one unit. When reaching an end portion of a
movement range in the main-scanning direction, the carriage 10
moves in an opposite direction in the main-scanning direction.
According to this, the carriage 10 reciprocates within the movement
range in the main-scanning direction. In addition, the movement
range in this case may be a movable range of the carriage 10 in the
main-scanning direction. In addition, a printing range may be set
according to the printing contents, and this printing range may be
set as the movement range.
[0056] On the other hand, when the carriage 10 moves up to the end
portion of the movement range and initiates movement in an opposite
direction in the main-scanning direction, the medium M moves in the
sub-scanning direction by a predetermined width in the sub-scanning
direction which is one unit during printing by the printer head 15.
The printer head 15 performs printing with the one unit set as one
PASS. That is, when the printer head 15 moves in the main-scanning
direction while ejecting the ink and reaches the end portion of the
movement range at a predetermined PASS, the medium M moves by one
PASS in the sub-scanning direction, and the printer head 15 moves
in an opposite direction in the main-scanning direction while
ejecting the ink. According to this, the printer head 15 performs
printing of next PASS.
[0057] As described above, when the printer head 15 ejects the ink
while moving in the main-scanning direction, the LED light sources
26 of the LED module 25, which moves in the main-scanning direction
together with the printer head 15, is turned on to emit light from
the LED light sources 26. The ink ejected onto the medium M is
exposed to the light and is cured by ultraviolet rays included in
the light from the LED light sources 26. The LED light sources 26
of the LED module 25 are arranged closely to the medium M, and thus
light from the LED light sources 26 reach the medium M without
being diffused too much. The ink on the medium M is exposed to the
light that is emitted from the near LED light sources 26 and
reaches the medium M without diffusion, and thus the ink is cured
by ultraviolet rays included in the light.
[0058] Here, in the LED module 25, the outer peripheral portion in
a plan view becomes the strong light amount portion 36, and the
central portion becomes the weak light amount portion 37, and thus
the medium M in the irradiation range of the LED module 25 can be
irradiated with light in an approximately uniform amount of light.
That is, in a case where the LED light sources 26 emit light, in
the ink-jet printer 1 according to the first embodiment, the light
reach the medium M without being diffused too much, but slight
diffusion occurs, and thus a part of the light during light
emission of the LED light sources 26 is emitted to the periphery of
the LED light sources 26. Therefore, a portion of the medium M,
which faces the weak light amount portion 37, is also irradiated
with a part of light from the strong light amount portion 36
located at the periphery of the weak light amount portion 37 in
addition to light from the weak light amount portion 37.
[0059] Similarly, a portion of the medium M, which faces the strong
light amount portion 36, is also irradiated with a part of light
from the weak light amount portion 37, but the light sources are
not arranged on an outer side of the strong light amount portion
36, and thus the portion is not irradiated with light from an outer
side of the strong light amount portion 36. Accordingly, the amount
of light emitted to the portion of the medium M, which faces the
weak light amount portion 37, from other than the weak light amount
portion 37, becomes larger than the amount of light emitted to the
portion of the medium M, which faces the strong light amount
portion 36, from other than the strong light amount portion 36.
Accordingly, the portion of the medium M, which faces the weak
light amount portion 37, is irradiated with light in a large
amount, but the amount of light in the weak light amount portion 37
is smaller than the amount of light in the strong light amount
portion 36. Accordingly, in the medium M, the portion facing the
weak light amount portion 37 and the portion facing the strong
light amount portion 36 are irradiated with light in substantially
the same amount of light, and in the medium M, an irradiation range
from one LED module 25 is irradiated with light in an approximately
uniform amount of light.
[0060] As described above, in the ink-jet printer 1 according to
the first embodiment, adjustment of the amount of light of the LED
light sources 26 is performed for each of a plurality of divided
areas, and the amount of light of the LED light sources 26 arranged
near the outer end portion of the LED module 25 is set to be larger
than the amount of light of the LED light sources 26 arranged near
the center of the LED module 25. Accordingly, each LED module 25
emits light in a uniform amount of light with respect to each
irradiation range. As described above, in a case where light is
emitted from the LED light sources 26 to the medium M, a part of
the light is reflected on a surface of the medium M, but the LED
light sources 26 are arranged closely to the medium M, and thus an
optical path of the reflected light is limited in the height
thereof. Accordingly, the reflected light that is reflected from
the medium M is less likely to diffuse, and thus the reflected
light is less likely to get out from a space between the medium M
and the LED module 25 to the outside.
[0061] When curing the ink with the light from the LED module 25,
full curing is performed after being subjected to temporary curing.
The temporary curing and the full curing are realized by adjusting
the amount of light from the LED module 25, or by performing
exposure of the ejected ink in combination with a plurality of the
LED modules 25 by appropriately moving the LED module 25 provided
to the outer rows 21out and the inner rows 21in of the ultraviolet
irradiation device 20, respectively, in the sub-scanning direction.
The amount of light during irradiation by the LED modules 25 or the
position of the LED modules 25 in the sub-scanning direction is
controlled by the control unit 35 in accordance with a printing
state.
[0062] With regard to the movement of the LED modules 25 in the
sub-scanning direction, for example, the temporary curing is
performed immediately after ejection onto the medium M from the
printer head 15, and when the carriage 10 moves to an end portion
to which the carriage 10 can move in the main-scanning direction,
and then moves in an opposite direction and returns to a position
at which the temporary curing of the ink is performed, the full
curing is performed. That is, the temporary curing is performed at
the same PASS as the PASS at which the ink is ejected from the
printer head 15, and the full curing is performed with respect to
the ink on the medium M which was subjected to the temporary curing
at the immediately previous PASS.
[0063] With regard to a combination of the LED modules 25 that
perform the temporary curing and the full curing, for example, at
the same position in the sub-scanning direction as that of the
ejection unit 16 ejecting the ink during current printing, only the
LED modules 25 of the inner row 21 in are located, and the LED
modules 25 in the outer rows 21out are not located. According to
this, immediately after ejecting the ink, exposure is performed by
only the LED modules 25 in the inner rows 21in, and thus the amount
of light is not great so much. As a result, the ink is not
completely cured, and thus the temporary curing is performed.
[0064] In the sub-scanning direction, the LED modules 25 in the
outer rows 21out are located at a position at which exposure can be
carried out with respect to the ink which is ejected onto the
medium M and is subjected to the temporary curing at the
immediately previous PASS. In addition, among the LED modules 25 in
the inner rows 21in, LED modules 25 different from the LED modules
25 that perform the temporary curing are also located at the same
position in the sub-scanning direction.
[0065] At the subsequent PASS after the PASS at which the temporary
curing of the ink is performed, exposure is performed with respect
to the ink by the LED modules 25 in the outer rows 21out and the
LED modules 25 in the inner rows 21in. According to this, at the
subsequent PASS after performing the temporary curing, exposure is
performed in an amount of light which is larger than the amount of
light during the temporary curing, and thus the ink is completely
cured. As a result, the full curing is performed. That is, the LED
modules 25, which perform the full curing, perform the exposure in
a state of being disposed at a position deviated by one PASS toward
the movement direction of the medium M in the sub-scanning
direction with respect to the LED modules 25 that perform the
temporary curing.
[0066] In addition, for each PASS, a movement direction of the
carriage 10 becomes an opposite direction in the main-scanning
direction, but the ultraviolet irradiation device 20 are arranged
on both sides of the printer head 15 in the main-scanning
direction, and thus the LED modules 25 that perform the exposure
with respect to the ink are exchanged for each PASS. For example,
when the temporary curing is performed by turning on the LED light
sources 26 of the LED modules 25 at an arbitrary PASS, at the
subsequent PASS, the temporary curing is performed by the LED
modules 25 of which position with respect to the printer head 15 in
the main-scanning direction becomes opposite.
[0067] In addition, the temporary curing or the full curing may be
carried out by a method other than the above-described method. With
regard to the temporary curing or the full curing, it is preferable
that the exposure by the LED modules 25 be performed by
appropriately adjusting the LED modules 25 that are used or the
amount of light in accordance with a material or form of a surface
of the medium M, ink that is used, and a desired finish state of
printing.
[0068] In the ink-jet printer 1 according to the first embodiment,
since the LED light sources 26 are arranged at positions close to
the medium M, it is possible to limit the height of the optical
path of reflected light from the medium M. Accordingly, it is
possible to suppress the light reflected from the medium M from
getting out from a space between the medium M and the LED modules
25 and being stray light directly propagating in the direction of
the printer head 15. In addition, the LED light sources 26 are
divided into a plurality of areas in accordance with an arrangement
position in each of the LED modules 25, and are independently
controlled for each of areas. Accordingly, adjustment of an amount
of light is performed for each of the areas, and thus an
irradiation range of the LED module 25 may be irradiated with light
in an approximately uniform amount of light. According to this, it
is possible to suppress occurrence of unevenness in irradiation
caused by arranging the LED light sources 26 to be close to the
medium M in order for light not to diffuse. As a result, it is
possible to perform irradiation of the ink-curing light while
greatly reducing the stray light.
[0069] In addition, since the LED light sources 26 are arranged
closely to the medium M, and thus the medium M may be efficiently
irradiated with irradiation light from the LED light source 26, and
thus it is possible to use small-output LED light sources 26. As a
result, small power consumption or a small amount of heat
generation may be realized.
[0070] In addition, the amount of light during light emission of
the LED light sources 26 is set to be different from each other in
accordance with the arrangement position of the LED light sources
26 so as to irradiate the irradiation range with light in an
approximately uniform amount of light, and thus it is possible to
suppress unevenness in curing of ink droplets landing on the medium
M due to irradiation unevenness in which the amount of light is
different in each irradiation position. As a result, it is possible
to make irradiation intensity of ultraviolet rays in an irradiation
range flat, and thus it is possible to cure the ink in a more
reliable and uniform manner.
[0071] In addition, the LED light sources 26 are allowed to emit
light in such a manner that the amount of light of the LED light
sources 26 arranged near the outer end portion of the LED module 25
is larger than that of the LED light sources 26 located near the
center of the LED module 25, and thus it is possible to irradiate
the irradiation range of the LED module 25 with light in a uniform
amount of light in a more reliable manner. As a result, it is
possible to make the irradiation intensity of ultraviolet rays in
the irradiation range flat in a more reliable manner, and thus it
is possible to cure the ink in a more reliable and uniform
manner.
[0072] In addition, the LED light sources 26 are arranged in such a
manner that a distance with the medium M becomes approximately 2
mm, and thus it is possible to limit the height of the optical path
of the reflected light from the medium M in a more appropriate
manner. Accordingly, it is possible to suppress the light reflected
from the medium M from being stray light directly propagating in
the direction of the printer head 15 in a more reliable manner. As
a result, it is possible to perform irradiation of the ink-curing
light while greatly reducing the stray light in a more reliable
manner.
Second Embodiment
[0073] An ink-jet printer 1 according to a second embodiment has
approximately the same configuration as the ink-jet printer 1
according to the first embodiment, but is characterized in that a
light absorption unit that absorbs light is provided between the
printer head 15 and the LED module 25. Other configurations are
similar to that of the first embodiment, and thus a description
thereof will not be repeated and the same reference numerals will
be given thereto.
[0074] FIG. 5 is a cross-sectional view of an LED module provided
to the ink-jet printer according to the second embodiment, and is
an explanatory view of the light absorption unit. As is the case
with the ink-jet printer 1 according to the first embodiment, in
the ink-jet printer 1 according to the second embodiment, the
plurality of LED light sources 26 are arranged in the LED module 25
to be close to the medium M. In addition, in the ink-jet printer 1
according to the second embodiment, the light absorption unit 41,
which is light absorption means for absorbing light reflected from
the medium M, is arranged on both sides of the LED module 25 in the
main-scanning direction. According to this, the light absorption
unit 41 is arranged also between the printer head 15 and the LED
module 25 in the main-scanning direction.
[0075] The light absorption unit 41 is arranged at a position
facing the medium M, that is, the light absorption unit 41 is
arranged at a position capable of receiving light that is emitted
from the LED light sources 26 and is reflected from the medium M.
That is, the light absorption unit 41 is formed as a surface facing
the medium M in a direction approximately parallel with the medium
M. According to this, the light absorption unit 41 can absorb light
reflected from the medium M.
[0076] Specifically, the light absorption unit 41 is coated with a
diffuse reflection coating material such as a black non-glossy
coating material. According to this, the light absorption unit 41
is less likely to reflect light received from the outside. That is,
the black color is a color capable of absorbing light of wavelength
of approximately all colors included in the light that is
irradiated, and light received from the outside is less likely to
be reflected. In addition, a surface of the diffuse reflection
coating material after coating has a fine concavo-convex shape, and
thus it is possible to reflect the light, which is emitted, in a
state of being diffused in various directions. Accordingly, light,
which is received from the outside, is less likely to be reflected
in a specific direction. According to this, the light absorption
unit 41 can absorb the light that is received from the outside
without reflecting the light in a specific direction. In addition,
in this case, the black color of the light absorption unit 41 is
not limited to an apparent black color, and may be a blackish color
such as gray. In addition, the black color that is stated here
represents a color having a reflection concentration capable of
absorbing 90% or more of wavelengths emitted from the LED light
sources 26, and it is preferable to have a reflection concentration
capable of absorbing 97% to 98% of a wavelengths emitted from the
LED light sources 26.
[0077] The ink-jet printer 1 according to the second embodiment is
configured as described above. Hereinafter, an operation thereof
will be described. When performing printing onto the medium M by
the ink-jet printer 1, the printer head 15 is moved in the
main-scanning direction while ejecting ink from the printer head
15. In addition, the LED light sources 26 of the LED module 25,
which moves together with the printer head 15 in the main-scanning
direction, are turned on to emit light from the LED light sources
26, thereby curing the ink on the medium M with ultraviolet rays
included in the light from the LED light sources 26.
[0078] Here, the LED light sources 26 are close to the medium M,
and thus the ultraviolet rays from the LED light sources 26 in a
case of turning on the LED light sources 26 of the LED module 25
reach the medium M without being diffused too much. The ultraviolet
rays reach the medium M in a direction that is approximately
perpendicular to a surface of the medium. M. According to this,
reflection from the surface of the medium M is less, but a part of
light is reflected from the surface of the medium M. The light
reflected in this manner repeats reflection between the medium M
and the LED module 25, and propagates in a direction of getting out
from a space between the medium M and the LED module 25.
[0079] A part of the light that repeats reflection, which
propagates in the main-scanning direction, is reflected from the
medium M at a position in the vicinity of an end portion of the LED
module 25 in the main-scanning direction, and propagates toward the
light absorption unit 41. Since the light absorption unit 41 is
coated with the black diffuse reflection coating material, light
that reach the light absorption unit 41 is not reflected too much
at the light absorption unit 41, and is absorbed at the light
absorption unit 41. The printer head 15 is located on end side of
the LED module 25 in the main-scanning direction, but the light
that propagates in the main-scanning direction while repeating
reflection is leaked from a space between the LED module 25 and the
medium M, and is absorbed at the light absorption unit 41 without
propagating toward the printer head 15. That is, the light that
propagates in the main-scanning direction while repeating
reflection is leaked from a space between the LED module 25 and the
medium M, and is absorbed at the light absorption unit 41 without
generation of stray light.
[0080] In the ink-jet printer 1 according to the second embodiment,
the light absorption unit 41 that absorbs light is arranged between
the printer head 15 and the LED module 25. Accordingly, it is
possible to suppress light, which is emitted from the LED module 25
and repeats reflection between the LED module 25 and the medium M,
from propagating in the direction of the printer head 15. As a
result, it is possible to perform irradiation of the ink-curing
light while greatly reducing the stray light.
[0081] In addition, the light absorption unit 41 is coated with the
diffuse reflection coating material. Accordingly, reflection of the
light, which reaches the light absorption unit 41, can be
suppressed in a more reliable manner, and thus it is possible to
suppress the light from a space between the LED module 25 and the
medium M from propagating toward the printer head 15. In addition,
the light absorption unit 41 is coated with a black color, and thus
the light, which reaches the light absorption unit 41, is absorbed
in a more reliable manner. According to this, it is possible to
suppress the light from propagating toward the printer head 15
between the LED module 25 and the medium M. As a result, it is
possible to perform irradiation of the ink-curing light while
greatly reducing the stray light in a more reliable manner.
Third Embodiment
[0082] An ink-jet printer 1 according to third embodiment has
approximately the same configuration as the ink-jet printer 1
according to the first embodiment, but is characterized in that an
incidence unit that transmits light is provided between the printer
head 15 and the LED module 25, and an incident light capturing unit
that captures light transmitted through the incidence unit is
provided. Other configurations are similar to that of the second
embodiment, and thus a description thereof will not be repeated and
the same reference numerals will be given thereto.
[0083] FIG. 6 is a cross-sectional view of an LED module provided
to the ink-jet printer according to the third embodiment, and is an
explanatory view of the incidence unit and the incident light
capturing unit. As is the case with the ink-jet printer 1 according
to the first embodiment, in the ink-jet printer 1 according to the
third embodiment, the plurality of LED light sources 26 are
arranged in the LED module 25 to be close to the medium M. In
addition, in the ink-jet printer 1 according to the third
embodiment, the light capturing unit 50, which captures light, is
provided across a surface opposite to a surface on an irradiation
side in the LED module 25 from both sides of the LED module 25 in
the main-scanning direction.
[0084] An inner side of the light capturing unit 50 is a space. The
space on the inner side of the light capturing unit 50 becomes an
incident light capturing chamber 52, which is an incident light
capturing unit formed across a surface opposite to a surface on a
side facing the medium M in the LED module 25 from lateral sides of
the LED module 25.
[0085] Among inner surfaces of the light capturing unit 50 which
form the incident light capturing chamber 52, each inner surface
located on a lateral side of the LED module 25 becomes a capturing
chamber inclined surface 53 that is a surface inclined both in a
direction parallel with the medium M such as the main-scanning
direction and the sub-scanning direction, and in a direction
perpendicular to the direction. The capturing chamber inclined
surface 53 is located on a lateral side of the LED module 25, and
becomes a surface inclined in directions facing both of the central
direction in a plan view of the LED module 25 and a direction in
which the medium M is arranged.
[0086] In addition, in the light capturing unit 50, the incidence
unit 51, which is a hole through which light reflected from the
medium M is transmitted, is formed at a position facing the medium
M on both sides of the LED module 25 in the main-scanning
direction. The incidence unit 51 is formed as a hole which
transmits light on a medium M side, and which communicates with a
space of a portion on the medium M side and the inner space of the
incident light capturing chamber 52. In addition, the incidence
unit 51 is formed at a portion that is located between the
capturing chamber inclined surface 53 of the incident light
capturing chamber 52 and the medium M in a direction perpendicular
to a direction parallel with the medium M during printing, that is,
in a direction perpendicular to a surface of the medium M.
According to this, the capturing chamber inclined surface 53 of the
incident light capturing chamber 52 is formed to face the medium M
through the incidence unit 51. The incident light capturing chamber
52 formed on an inner side of the light capturing unit 50 is
configured to receive light, which is incident to the inside
through the incidence unit 51 from the medium M side, at the
capturing chamber inclined surface 53, thereby capturing the light
inside the incident light capturing chamber 52.
[0087] The ink-jet printer 1 according to the third embodiment is
configured as described above. Hereinafter, an operation thereof
will be described. When performing printing onto the medium M by
the ink-jet printer 1, the LED light sources 26 of the LED module
25 are turned on while ejecting ink from the printer head 15,
thereby curing the ink on the medium M with ultraviolet rays
included in the light from the LED light sources 26.
[0088] In addition, a part of light during light emission of the
LED light sources 26 of the LED module 25 is reflected from a
surface of the medium 1M and repeats reflection between the medium
M and the LED module 25, and propagates in a direction of getting
out from a space between the medium M and the LED module 25. A part
of the light that repeats reflection, which propagates in the
main-scanning direction, is reflected from the medium M at a
position in the vicinity of an end portion of the LED module 25 in
the main-scanning direction, and propagates toward the incidence
unit 51 of the light capturing unit 50. The incidence unit 51 is a
hole that communicates with the inside of the incident light
capturing chamber 52 and the space at the portion on the medium M
side, and thus the light reaching the incidence unit 51 enters the
incident light capturing chamber 52 through the incidence unit
51.
[0089] First, the light that enters the incident light capturing
chamber 52 reaches the capturing chamber inclined surface 53, which
faces the medium M, through the incidence unit 51. The capturing
chamber inclined surface 53 is inclined in a direction
perpendicular to the surface of the medium M, and thus the light
reaching the capturing chamber inclined surface 53 is reflected
toward a direction other than the direction of the medium M.
According to this, the light, which enters the incident light
capturing chamber 52, is reflected in an inner direction of the
incident light capturing chamber 52 due to the capturing chamber
inclined surface 53, reaches another inner surface of the incident
light capturing chamber 52, and is reflected again from the inner
surface.
[0090] In the incident light capturing chamber 52, as a
communication unit that communicates with the outside, only the
incidence unit 51 is formed, and thus the light, which enters the
incident light capturing chamber 52 and is reflected from the inner
surface of the incident light capturing chamber 52, does not get
out to the outside from the incidence unit 51, and repeats
reflection from the inner surface of the incident light capturing
chamber 52. The light, which enters the incident light capturing
chamber 52, is attenuated during repeating the reflection inside
the incident light capturing chamber 52 as described above.
According to this, the incident light capturing chamber 52 captures
light, which is transmitted through the incidence unit 51, on the
medium M side, and the light capturing unit 50 absorbs the light
inside the incident light capturing chamber 52 in accordance with
the capturing of the light in the incident light capturing chamber
52.
[0091] The printer head 15 is located on one end side of the LED
module 25 in the main-scanning direction, but the light, which
propagates in the main-scanning direction while repeating
reflection, enters the incident light capturing chamber 52 from the
incidence unit 51 without being leaked from a space between the LED
module 25 and the medium M and propagating toward the printer head
15, and is absorbed in the incident light capturing chamber 52.
That is, the light that propagates in the main-scanning direction
while repeating reflection is captured by the light capturing unit
50 without being leaked from a space between the LED module 25 and
the medium M and becoming the stray light.
[0092] The ink-jet printer 1 according to the third embodiment is
provided with the incident light capturing chamber 52 adsorbing
light, which is transmitted through the incidence unit 51, on the
medium M side, and thus it is possible to capture more light. That
is, since the incident light capturing chamber 52 reflects the
light, which is transmitted through the incidence unit 51, at the
capturing chamber inclined surface 53 in a direction other than the
medium M, it is possible to attenuate the light by reflecting the
light at a large area while trapping the light, and thus it is
possible to capture more light. According to this, it is possible
to reduce the stray light in the direction of the printer head 15
from the LED module 25 side in a more reliable manner. As a result,
it is possible to perform irradiation of the ink-curing light while
greatly reducing the stray light in a more reliable manner.
Modification Example
[0093] In addition, in the above-described ink-jet printer 1, the
plurality of LED light sources 26 of the LED module 25 are divided
into eight areas, and each of the areas is independently
controlled. However, the division type of the LED light sources 26
may be a type other than the above-described type. FIG. 7 is an
explanatory view in a case of controlling the LED light sources in
a 12-division manner as a modification example of the ink-jet
printer according to the first embodiment. For example, as shown in
FIG. 7, the plurality of LED light sources 26 provided to the LED
module 25 may be divided into twelve (F1 to F12) in such a manner
that the LED light sources 26 are divided into three in the
main-scanning direction and are divided into four in the
sub-scanning direction, and each set may be independently
controlled. In this case, outer peripheral 10 sets, which include
each one row on both sides in the main-scanning direction (F1 to
F4, and F9 to F12), and each one row on both sides in the
sub-scanning direction (F1, F5, F9, F4, F8, and F12), may be set to
the strong light amount portion 36, and two sets (F6 and F7), which
are located at the central portion in both of the main-scanning
direction and the sub-scanning direction, may be set as the weak
light amount portion 37.
[0094] FIG. 8 is an explanatory view in a case of controlling the
LED light sources in an 8-division manner as a modification example
of the ink-jet printer according to the first embodiment. For
example, as shown in FIG. 8, the LED light sources 26 may be
divided into eight (G1 to G8) in such a manner that the LED light
sources 26 are divided into three in the main-scanning direction,
each portion located on both sides in the main-scanning direction
is divided into two in the sub-scanning direction, and a portion
located at the center in the main-scanning direction is divided
into four in the sub-scanning direction. In this case, outer
peripheral six sets, which include each one row on both sides in
the main-scanning direction (G1, G2, G7, and G8) and each one row
on both sides in the sub-scanning direction (G1, G3, G7, G2, G6,
and G8), may be set as the strong light amount portion 36, and two
sets (G4 and G5) located at the central portion in both of the
main-scanning direction and the sub-scanning direction may be set
as the weak light amount portion 37.
[0095] In addition, the LED module 25 may be configured in a
configuration other than the configuration in which the strong
light amount portion 36 is provided to surround the weak light
amount portion 37. FIG. 9 is an explanatory view in a case of
controlling the LED light sources in a 5-division manner as a
modification example of the ink-jet printer according to the first
embodiment. For example, as shown in FIG. 9, the LED module 25 may
be divided into five (H1 to H5) by division into five in the
main-scanning direction. In this case, a total of two sets (H1 and
H5), which include each one set on both sides in the main-scanning
direction, may be set as the strong light amount portion 36, and
one set (H3) located at the center in the main-scanning direction
may be set as the weak light amount portion 37. In addition, two
sets (H2 and H4) each being located between the strong light amount
portion 36 and the weak light amount portion 37 in the
main-scanning direction may be set as an intermediate light amount
portion 38 in which the amount of light is set to be weaker than
that of the strong light amount portion 36 and the amount of light
is set to be stronger than that of the weak light amount portion
37, that is, the amount of light becomes an intermediate light
amount between the strong light amount portion 36 and the weak
light amount portion 37.
[0096] FIG. 10 is an explanatory view in a case of controlling the
LED light sources in a 4-division manner as a modification example
of the ink-jet printer according to the first embodiment. For
example, as shown in FIG. 10, the LED module 25 may be divided into
four (J1 to J4) by division into four in the main-scanning
direction. In this case, a total of two sets (J1 and J4), which
include each one set on both sides in the main-scanning direction,
may be set as the strong light amount portion 36, and two sets (J2
and J3) located on the central side in the main-scanning direction
may be set as the weak light amount portion 37.
[0097] Even when dividing the area during control of the LED light
sources 26 like anyone of the modification examples, the amount of
light is set in such a manner that the amount of light of the LED
light sources 26 arranged near the outer end portion of the LED
module 25 in the main-scanning direction becomes larger than that
of the LED light sources 26 arranged near the center of the LED
module 25, and thus the irradiation range of the LED module 25 can
be uniformly irradiated with light. According to this, it is
possible to make irradiation intensity of ultraviolet rays flat,
and thus it is possible to improve printing quality.
[0098] In addition, in contrast, the LED light sources 26 may be
set in such a manner that the amount of light of the LED light
sources 26 located near the center of the LED module 25 in the
main-scanning direction becomes larger than that of the LED light
sources 26 arranged near the outer end portion of the LED module 25
in the main-scanning direction. Specifically, the area during
control of the LED light sources 26 is divided, and the position
near the end portion of the LED module 25 in the main-scanning
direction or the position near the end portion of the LED module 25
in the sub-scanning direction may be set as the weak light amount
portion 37, and the position near the center in the main-scanning
direction or the sub-scanning direction may be set as the strong
light amount portion 36. In this manner, when reducing the amount
of light of the LED light sources 26 arranged near the outer end
portion of the LED module 25 in the main-scanning direction, light
that propagates toward the printer head 15 can be reduced, and thus
it is possible to reduce the stray light in a more reliable
manner.
[0099] In this manner, it is preferable that the amount of light
for each position in the LED module 25, that is, the amount of
light for each of the areas divided into plural sections be
appropriately set in accordance with a printing type, a device
configuration, and a performance regarded as important.
[0100] In addition, in the ink-jet printers 1 according to the
first to third embodiments, the ultraviolet irradiation device 20
includes the inner rows 21in and the outer rows 21out on both sides
of the printer head 15 in the main-scanning direction, and the LED
module 25 is provided thereto, respectively. However, the
ultraviolet irradiation device 20 may be configured in a type other
than the above-described type. When the LED light sources 26 of the
LED module 25 are arranged to be close to the medium M, and the
amount of light is set to be different in accordance with each
arrangement position regardless of the configuration of the
ultraviolet irradiation device 20, it is possible to make the
reduction in the stray light and the flattening of the irradiation
intensity of ultraviolet rays compatible with each other.
[0101] In addition, in the ink-jet printer 1 according to the
second embodiment, the light absorption unit 41 is coated with a
black diffuse reflection coating material, but the light absorption
unit 41 may be subjected to a process other than the coating
process. For example, the light absorption unit 41 may be subjected
to surface texturing in order for a surface to have a
concavo-convex shape. The type of the light absorption unit 41 does
not matter as long as the light absorption unit 41 can absorb light
from the medium M side without reflecting so much.
[0102] In addition, the ink that is ejected from the ejection units
16 of the printer head 15 is cured by ultraviolet rays included in
light that is emitted from the LED light sources 26, and thus the
light absorption unit 41 may be configured not to reflect,
particularly, the ultraviolet rays in the light that reaches the
light absorption unit 41 from the medium M side. For example, an
ultraviolet absorbing agent that absorbs ultraviolet rays may be
applied onto the light absorption unit 41. Specifically, a cerium
oxide-based inorganic ultraviolet absorbing agent such as Needral
(registered trademark) manufactured by Taki Chemical Co., Ltd. may
be applied onto the light absorption unit 41. According to this,
when receiving light reflected from the medium M side, the light
absorption unit 41 can absorb ultraviolet rays included in the
light, and thus it is possible to suppress unnecessary ultraviolet
rays from being emitted in the printer head 15 from a space between
the LED module 25 and the medium M, and it is possible to suppress
the ultraviolet rays from being the stray light.
[0103] In addition, in the ink-jet printer 1 according to the
second embodiment, the light absorption unit 41 is formed in a
direction that is approximately parallel with the medium M, but the
light absorption unit 41 may be formed in other directions. FIG. 11
is an explanatory view of a light absorption unit as a modification
example of the ink-jet printer according to the second embodiment.
For example, as shown in FIG. 11, as it is spaced away from the LED
module 25 in the main-scanning direction, the light absorption unit
41 may be formed to be inclined in a direction closing to the
medium M. When the light absorption unit 41 is inclined in the
direction facing the LED module 25 side as described above, it is
possible to reflect the light, which is not absorbed by the light
absorption unit 41 and is reflected from the light absorption unit
41, toward a side at which the LED module 25 is located. According
to this, it is possible to suppress the light, which propagates in
the main-scanning direction while repeating reflection between the
LED module 25 and the medium M, from getting out from a space
therebetween, and propagating toward the printer head 15, and thus
it is possible to reduce the stray light in a more reliable
manner.
[0104] In addition, in the ink-jet printer 1 according to the third
embodiment, a topology of the inner surface of the incident light
capturing chamber 52 provided to the light capturing unit 50 is not
particularly limited, but the type of the inner surface of the
incident light capturing chamber 52 may be a type that is less
likely to reflect light. The inner surface of the incident light
capturing chamber 52 may be coated with a black diffuse reflection
coating material similar to the light absorption unit 41 provided
to the ink-jet printer 1 according to the second embodiment, may be
subjected to the surface texturing to have a concavo-convex
surface, or an ultraviolet absorbing agent may be applied onto the
inner surface. According to this, when light, which enters the
incident light capturing chamber 52, reaches the inner surface of
the incident light capturing chamber 52, the inner surface is less
likely to reflect the light, or can absorb ultraviolet rays.
Accordingly, it is possible to capture the light, which enters the
incident light capturing chamber 52 through the incidence unit 51,
in the incident light capturing chamber 52 in a more reliable
manner, or it is possible to absorb the ultraviolet rays.
Accordingly, it is possible to reduce the stray light in a more
reliable manner.
[0105] In addition, in the ink-jet printer 1 according to the
second and third embodiments, the light absorption unit 41 or the
incidence unit 51 of the light capturing unit 50 is arranged on
both sides of the LED module 25 in the main-scanning direction.
However, the light absorption unit 41 or the incidence unit 51 may
be an installation type other than the above-described installation
type. For example, the light absorption unit 41 or the incidence
unit 51 may also be arranged on both sides of the LED module 25 in
the sub-scanning direction. In addition, the light absorption unit
41 or the incidence unit 51 may also be arranged only at a position
between the printer head 15 and the LED module 25 in the
main-scanning direction. An installation type in other portions
does not matter as long as the light absorption unit 41 or the
incidence unit 51 is arranged at a position between the printer
head 15 and the LED module 25 at least in the main-scanning
direction.
[0106] In addition, the ink-jet printer 1 may be appropriately
configured in combination of the configurations used in the
above-described embodiments and modification examples, and the
like, or may use a configuration other than the above-described
configuration. When a plurality of LED light sources 26 are
arranged at a position near the medium M, and the amount of light
during light emission is set to be different in accordance with
each arrangement position regardless of the configuration of the
ink-jet printer 1, and the like, it is possible to perform
irradiation of the ink-curing light while greatly reducing the
stray light.
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